Monday, 21 October 2013

Summary: Aquaponic system bio-filter crash likely caused by chloramine poisoning of bacteria, which then led to buildup of high levels of ammonia. Subsequent treatments to reduce ammonia in the system ultimately proved ineffective. Follow us through our trials and tribulations as we tried to avert an aquaponist’s nightmare scenario.

Chapter 3: Vital Life Signs?
Things appeared to turn for the better. It seemed that constant water changes caused the tilapia to slowly come out their ammonia induced stupor and they began eating once more. As well, the system experienced occasional rapid drops in pH, signs that our bacterial solution infusions has brought back the beneficial bacteria colonies.

It appeared that our jubilations were premature however, as this story reached a false ending. When water samples were assessed, nitrite levels were zero and ammonia levels remained beyond 8ppm in the plant bed. We debated amongst ourselves whether to connect the fish tank back to the plant bed and recommenced the connected cycling of our system. The daily water changes were able to lower the ammonia levels in the fish tank—at least momentarily, and separation of the plant bed, while adding bases, should have allowed for a more rapid cycling. Yet, the observed results did not reflect the justification for separating the fish tank from the plant bed.

The constant water changes to the fish tank did not reduce the ammonia level, which was ~4ppm, to the optimum level of 0ppm. Furthermore, after targeted bacterial infusions and water treatment to the plant bed, the ammonia levels in the plant bed and the fish tank were never really significantly different. Based on these facts and weighing the various factors listed in our decision matrix, the decision to separate the the fish tank from the plant bed did not seem sensibly warranted: our continuous efforts to lower the system's total ammonia, which would not have bothered us, did little to ameliorate the system’s overall condition. Therefore, the plant bed and the fish tank were reconnected. But the pressing issue was still not resolved and it was time to recommence the discovery process...